Why Reusing Fiberglass Insulation in Your Crawl Space Could Be a Costly Mistake

Ready to transform your crawl space and avoid costly mistakes? Join us as Michael Church from Crawl Space Ninjas uncovers the truth about reusing fiberglass insulation. Many contractors might suggest it's okay to reuse, but is that really the best practice? We'll break down the types of insulation commonly found in homes—rock wool, fiberglass, and spray foam—and explain why compromised insulation can lead to problems like moisture damage, mold, and reduced effectiveness. Get expert advice on how to handle wet and damaged insulation, especially if you're considering sealing and dehumidifying your crawl space.

We dive into the specifics of why removing old, compromised insulation is crucial, and the best alternatives for both vented and sealed crawl spaces. Learn why subfloor insulation is a necessity for vented spaces due to building codes, and discover the benefits of foam board and insole barrier insulation for sealed environments. Michael shares actionable tips that will help you ensure your home remains efficient and healthy. Don't miss out on these essential insights that could save you time and money in the long run.

Check out Michael's book, "Crawl Space Repair Myths-Busted" now available on Amazon!

Need help: https://crawlspaceninja.com or https://diy.crawlspaceninja.com

Transcript

Speaker 1: 0:00

Hey, michael Church Crawl Space Ninjas. Today we're continuing our misconception series about should you reuse that fiberglass insulation? There's a lot of contractors out there that will reuse subfloor insulation. Is that a good idea? Stay tuned Many times when we're talking to homeowners about properly insulating the crawl space. Most homes built today are built with subfloor insulation that could either be rock, wool or fiberglass. And then you got some companies that are spray foaming the subfloor and different things like that.

Speaker 1: 0:35

Normally by the time we go in to address a crawl space, it's got mold and high humidity and even some standing water. So by that time the insulation is already soaking, wet and dripping and even what we call stalactiting, where you can see the fiberglass is starting to pull away from the insulation and looks like little stalactites that are hanging down from the subfloor. So you should never reuse that insulation. If it's moist it's already been compromised. The R-value has already started to deteriorate. Anytime fiberglass gets wet it affects the R-value. So what we do in that situation especially if you're going to encapsulate the crawlspace, seal the crawlspace, install dehumidification and that sort of thing just take that insulation out, because normally you have to get it out in order to dry out the subfloor and possibly address mold. So take the insulation out, bag it and throw it away and then install a foam board or an insole barrier insulation on the walls instead of putting subfloor insulation back.

Speaker 1: 1:39

Now if you have an open crawl space and you have that same scenario, you can't insulate the walls. You need to put subfloor insulation back because of code. So if your crawl space is vented, you have to have subfloor insulation. If your crawl space is sealed, you can do wall insulation instead of subfloor insulation, but never reuse fiberglass or rock wool. You can reuse foam board, because foam board is actually designed to be wet and be installed below grade, so that's okay. If you have to take the foam board off the wall, you can reuse it. Michael Church Crawl Space Ninja. We hope you make it a happy and blessed day. We'll see you later.